A study of the effect of model geometry and lubricant rheology upon the elastohydrodynamic lubrication performance of metal-on-metal hip joints

2008 ◽  
Vol 222 (3) ◽  
pp. 493-501 ◽  
Author(s):  
W-Z Wang ◽  
Z M Jin ◽  
D Dowson ◽  
Y Z Hu
Keyword(s):  
Elastohydrodynamic Lubrication ◽  
Hip Joints ◽  
Metal On Metal ◽  
Lubrication Performance ◽  
Model Geometry ◽  
Lubricant Rheology

The effect of aspherical geometry and surface texturing on the elastohydrodynamic lubrication of metal-on-metal hip prostheses under physiological loading and motions

2010 ◽  
Vol 224 (12) ◽  
pp. 2627-2636 ◽  
Author(s):  
L M Gao ◽  
Q E Meng ◽  
F Liu ◽  
J Fisher ◽  
Z M Jin
Keyword(s):  
Hip Replacement ◽  
Numerical Solutions ◽  
Surface Texturing ◽  
Elastohydrodynamic Lubrication ◽  
Bearing Surface ◽  
Wear Rates ◽  
Physiological Loading ◽  
Metal On Metal ◽  
Head Surface ◽  
Lubrication Performance

As an alternative material combination, metal-on-metal (MOM) hip replacement has attracted a revived interest due to its very low wear rates. In this article, an elastohydrodynamic lubrication analysis is performed for an MOM hip replacement with specific geometrical designs: a macro Alpharabola geometry of the cup bearing surface and micro-dimples on the head surface. The corresponding numerical methodology is presented and full numerical solutions are obtained. The effect of the macro- and micro-geometrical designs on the lubrication performance is investigated, under both simplified and physiological walking conditions. The real physiological loading and motion conditions are important to be considered when optimizing the conformity-associated geometry of hip bearings. The Alpharabola geometry of cup bearing surface is found to significantly improve the lubricating film thickness and reduce hydrodynamic pressure of MOM hip implants, when the Alpharabola minimum radius is aligned with the loading direction. Dimpled surface texturing has an adverse effect in a fluid film lubrication regime under the conditions considered in this study.

Isoviscous elastohydrodynamic lubrication of circular point contacts with particular reference to metal-on-metal hip implants

2003 ◽  
Vol 217 (5) ◽  
pp. 397-402 ◽  
Author(s):  
D Jalali- Vahid ◽  
Z. M. Jin ◽  
D Dowson
Keyword(s):  
Numerical Solutions ◽  
Elastohydrodynamic Lubrication ◽  
Hip Implants ◽  
Point Contacts ◽  
Hip Joints ◽  
Circular Point ◽  
Metal On Metal ◽  
Artificial Hip Joints

A full numerical analysis of elastohydrodynamic lubrication (EHL) of circular point contacts was carried out in the present study under isoviscous conditions with particular reference to metal-on-metal artificial hip joints, using a modified Newton-Raphson method. It was found to be possible to incorporate directly the physiological conditions, representative of typical metal-on-metal hip implants under in-vivo walking or in-vitro simulator testing, in the present numerical solutions. The predicted minimum and central film thicknesses were compared favourably with those estimated from various formulae available in the literature. In particular, it was shown that both the minimum and the central film thickness expressions derived by Hamrock and Dowson were reasonably accurate for all the conditions considered in the present study.

Elastohydrodynamic Lubrication of Aspherical Metal-on-Metal Artificial Hip Joints

2009 ◽  
pp. 833-834
Author(s):  
Qingen Meng ◽  
Leiming Gao ◽  
Feng Liu ◽  
Peiran Yang ◽  
Fisher John ◽  
...  
Keyword(s):  
Elastohydrodynamic Lubrication ◽  
Hip Joints ◽  
Metal On Metal ◽  
Artificial Hip ◽  
Artificial Hip Joints

Plasto ‐elastohydrodynamic lubrication performance of greased ellipsoid contact

2021 ◽  
Author(s):  
Yong Zheng ◽  
Changqing Wang ◽  
Chao Pu ◽  
Jiayu Gong ◽  
Fanming Meng
Keyword(s):  
Elastohydrodynamic Lubrication ◽  
Lubrication Performance

A Starved Mixed Elastohydrodynamic Lubrication Model for the Prediction of Lubrication Performance, Friction and Flash Temperature With Arbitrary Entrainment Angle

2017 ◽  
Vol 140 (3) ◽  
Author(s):  
Wei Pu ◽  
Dong Zhu ◽  
Jiaxu Wang
Keyword(s):  
Surface Roughness ◽  
Film Thickness ◽  
Elastohydrodynamic Lubrication ◽  
Industrial Applications ◽  
Operating Conditions ◽  
Flash Temperature ◽  
Machined Surface ◽  
Lubrication Performance ◽  
Wide Range ◽  
Starved Lubrication

In this study, a modified mixed lubrication model is developed with consideration of machined surface roughness, arbitrary entraining velocity angle, starvation, and cavitation. Model validation is executed by means of comparison between the obtained numerical results and the available starved elastohydrodynamic lubrication (EHL) data found from some previous studies. A comprehensive analysis for the effect of inlet oil supply condition on starvation and cavitation, mixed EHL characteristics, friction and flash temperature in elliptical contacts is conducted in a wide range of operating conditions. In addition, the influence of roughness orientation on film thickness and friction is discussed under different starved lubrication conditions. Obtained results reveal that inlet starvation leads to an obvious reduction of average film thickness and an increase in interasperity cavitation area due to surface roughness, which results in significant increment of asperity contacts, friction, and flash temperature. Besides, the effect of entrainment angle on film thickness will be weakened if the two surfaces operate under starved lubrication condition. Furthermore, the results show that the transverse roughness may yield thicker EHL films and lower friction than the isotropic and longitudinal if starvation is taken into account. Therefore, the starved mixed EHL model can be considered as a useful engineering tool for industrial applications.

Effect of tooth waist order parameters of double involute gears on lubrication performance of gear drive

2016 ◽  
Vol 68 (6) ◽  
pp. 671-675 ◽  
Author(s):  
Zhimin Fan ◽  
Wanfeng Zhou ◽  
Ruixue Wang ◽  
Na Wang
Keyword(s):  
Elastohydrodynamic Lubrication ◽  
Reference Value ◽  
Tooth Profile ◽  
Order Parameters ◽  
Content Type ◽  
Oil Film ◽  
Gear Drive ◽  
Involute Gear ◽  
Lubrication Performance ◽  
Involute Gears

Purpose The purpose of this paper is to derive a new lubrication model of double involute gears drive and study the effect of the tooth waist order parameters of double involute gears on lubrication performance. Design/methodology/approach The new lubrication model of double involute gears drive was established according to the meshing characteristics of double involute gears drive and the finite length line contact elastohydrodynamic lubrication theory. Numerical calculation of the lubrication model of gear drive was conducted using the multigrid method. Findings The results show that the oil film necking phenomenon and the oil film pressure peak emerged at the tooth waist order area and the tooth profile ends, and when compared with involute gear, the lubrication performance at the tooth waist order area is better than that at the tooth profile ends. The effect of tooth waist order parameters on lubrication performance at the tooth waist order area was greater than that at other areas. Originality/value This research will promote the application of the double involute gear as soon as possible, and it has the reference value for other types of gears.

Effect of pin generatrix on the elastohydrodynamic lubrication performance of pin-bush pair in industrial roller chains

2021 ◽  
pp. 135065012110659
Author(s):  
Ansheng Zhang ◽  
Jing Wang ◽  
Yiming Han ◽  
Jianjun Zhang ◽  
Yi Liu
Keyword(s):  
Film Thickness ◽  
Working Condition ◽  
Elastohydrodynamic Lubrication ◽  
Test Rig ◽  
Stroke Length ◽  
Oil Supply ◽  
Supply Condition ◽  
Lubrication Performance ◽  
Custom Made ◽  
Disk Test

For industrial roller or bush chains, the bush swings relative to the pin at working condition. If proper lubrication is maintained, an elastohydrodynamic lubrication contact is formed between the pin and the bush. In this study, a custom-made pin was used to replace the steel ball of a ball-disk test rig and optical interferometric experiments were carried out to study the effect of pin generatrix on the lubrication performance. The effects of generatrix shape, stroke length and oil supply condition on the lubrication state were explored. It is found that the change of the generatrix has an important influence on the oil film thickness, especially under rare oil supply condition.

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